<!-- 开发环境版本，包含了有帮助的命令行警告 -->
<script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
<!-- 生产环境版本，优化了尺寸和速度 -->
<script src="https://cdn.jsdelivr.net/npm/vue@2"></script>
<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>第一个vue程序</title>
</head>

<body>
    <div id="app">
        <!-- 插值表达式 -->
        {{message}}
    </div>
</body>
<script src="https://cdn.jsdelivr.net/npm/vue@2/dist/vue.js"></script>
<script>
    let app = new Vue({
        el: "#app",
        data: {
            message: "你好 , 朋友!"
        }
    })
</script>

</html>